Metallic vapor rectifier



March 1, 1932. s. WIDMER METALLIC VAPOR RECTIFIER Filed Sept. 15, 1929lNVfNTOR S TEM/V Wm MFR Patented Mar. 1, 1932 UNITED STATES PATENTOFFICE swarm WIDMER, or BADEN, SWITZERLAND, 'nssrcrron T0n'x'rrmmmnnmcmrr BROWN rovnar & em, or BADEN, SWITZERLAND, A JOINT-STOCKcomrm or SWITZERLAND METALLIC VAPOR nrzc'rrrmn Application filedSeptember 13, 1929, Serial No. 82,424, and in Germany September 20,1928.

This invention relates to improvements in electric current rectifiers ofthe metallic vapor type and, more particularly, to arrangements andconstructions therein for preventing the flow of reverse currentsor-so-called backflres therethrough.

The temperature in the operating arc chamber of a metallic vaporelectric current rectifier is sufliciently high to cause vaporization oflarge quantities of the fluid metallic cathode which is usually mercury.It is necessary to condenseand returnthegreaterportion of the vaporizedmercury to the cathode well, for which purpose the walls of theoperating chamber and of a condensation dome arranged in connectiontherewith are usually formed as double walled to provide for thecirculation of a cooling medium therethrough. The vaporized mercurycontacts with all portions ofthe inner surfaces of the cooled wall isaccordingly condensed and flows back to the cathode well. The portion ofthe mercury condensed on the inner surfaces of the condensation domemust, however, drop a comparatively great distance to the bottom of therectifying chamber and into the cathode well of the rectifying structureso that a portion of the globules of the condensed mercury are broken upand are thrownin all directions whereby a portion of the mercury maycome into contact with either the are guides surrounding the anodes orthe anodes themselves. The contacting of a drop of fluid mercury oneither the arc guides or on the anodes forms a spot which is negative tothe anode potential and, therefore, permits a short circuit or backfire-The dropping of mercury from the upper portions of the wall of theoperating space and the inner surfaces of the condensation dome with theattendant splashing thereof also increases the amount of mercuryvaporized thereby increasing the vapor density within the operatingspace of the rectifier so that the danger of reverse currents orbackfires is further increased.

It is, accordingly, among the objects of the present invention toprovide an electric current rectifying structure of the type utilizingmetallic vapor as the rectifying agent which structure will preventbreaking up of the vaporized cathode material condensed on V anddropping from the upper portions of the structure to the lower portionsthereof.

A further object of the invention is to provide for the collectionandconduction of condensed cathode material'to the cathode rounding theanodes.

Objects and advantages, other than those above set forth, will beapparent from the following description and the drawings in which Figure1 is a vertical view, partially in section, of one embodiment of theinvention, and

Fig. 2 is a horizontal sectional view along lines a, a ofFig. 1.

Referring more particularly to the drawings by characters of reference,the reference numerals 1 and 2 indicate respectively the side and bottomportions of a tank forming a portion of the rectifying structure. Theside and bottom portions of the tank are formed with double walls topermit the circulation of a cooling medium therethrough.

An annulus 3 of insulating material extends in sealed relation, into anaperture in the bottom of the tank, which aperture is locatedsubstantially centrally therein and is closed by a bottom plate 4 toform a cathode well extending below the inner surface of the bottom ofthe tank to receive the cathode material 5 which is preferably mercury.The

tank is closed by a cover member 6 having rectifying structure.

into the channel 14 is discharged. therefrom anodes 8 are partiallyenclosed by means of arc guides 9, which extend into suitable closelyadjacent relation to the bottom 1. A substantially horizontal partitionmember 11 extends across the tank between the side walls thereof andabove the open ends of the arc guides. The member 11 is formed with anaperture therethrough which has the edge thereof turned upwardly to forma chan- 1 2 V The upturned inner edge surrounding the aperture throughthe horizontal partition 11 is so formed that the cathode materialcondensing in the dome 7 and dropping on the partition 11 is collectedin the channel 12.

. The condensed fluidmercury is discharged from the channel 12 by meansof a tube 13 into a channel 14 formed about the side walls 1 at theirjunction with the bottom 2 of the The mercury flowing into the cathodewell by means of a conduit 16. It will be seen that all of the mercurycondensed in the condensation dome, on the top and on the upper portionsof the side walls of the structure is collected by the channel 12 and isconducted by way of tube 13, channel '14, and tube 16 to the cathodewell, so that dropping of' globulesof mercury from the condensation dometo the bottom of the rectifier is prevented. The mercury condensing onthe side walls of the rectifier tank is likewise collected in thechannel 14 and conveyed to the cathode well through the conduit 16 sothat the flow of mercury over the bottom of the tank into the cathodewell is prevented and the mercury is accordingly kept out of contactwith the electric are. A plurality of guides 17, in the form of ribs,are arranged adjacent channel 14:

and the point of the arc guide closest to the side walls of the tank forthe purpose of guiding any mercury condensed on the bottom surface ofthe tank to'the cathode well by a path away from the path of the arc.

' It will be apparent that the structure, according to the presentinvention, provides means for collecting the condensed cathode materialfrom the condensation dome, the top and the side walls of a rectifyingstructure and conducting such condensed cathode material to the cathodewell out of contact with the electric arc in such manner that none ofthe mercury is broken up by dropping from a relatively great height sothat splashing of mercury on the anodes or the are guides and theformation of cathode spots thereby is completely avoided. Such structurenot only prevents the formation of cath ode spots on the anode structureof the rectifying device but likewise tends to decrease the vapordensity within operating space of the rectifier so that accidentalcondensation of excessive quantities of mercury vapor on the anodes orthe arctguides is avoided.

Although only one embodiment of this invention has been illustrated anddescribed, it will be understood that various other embodiments arepossible, and that various other changes may be made without departingfrom the spirit of the invention or the scope of the claims.

The invention claimed is:

1. In an electrical current rectifying device, a container forming anoperating chamber, a plurality of anodes extending into the said chamberfromthe top portion thereof, sleeves surrounding each of the said anodesand provided with openings in the direction of the bottom of thecontainer, a cathode formed of vaporizable material within the saidcontainer, a partition having a circular channel arranged horizontallyacrossthe container above the openings of the said sleeves forcollecting portions of the said cathode material condensed abovevthe'said channel, a channel arranged adjacent the junction of the sidewalls and the bottom of said container'to receive vaporized cathodematerial condensed on the said Walls, and means interconnecting the saidchannels for conveying the condensed cathode material collected thereinto the said cathode.

2. In an electrical current rectifying device, a container forming anoperating Chain ber, a plurality of anodes extending into the saidchamber, sleeves surrounding each of the said anodes and provided withopenings in the direction of the bottom of the said container, a cathodeformed of vapor-gable material within the said container, a partitionarranged across the said container and having a channel above the saidopenings of the said sleeves for collecting portions of the said cathodematerial condensed above the said partition, a channel arranged adjacentthe junction of the side walls and bottom surface of the said containerto receive vapor-- ized cathode material condensed on the said sidewalls, means interconnecting the said channels for conveying thecondensed cathode material collected therein to the said cathode, and aplurality of guides arranged ad jacent the bottom surface of the saidcon: tainer for collecting and guiding condensed cathode material to thecathode via paths away from the path of the are.

In testimony whereof I have hereunto subscribed my name this 27th day ofAugust,

. STEFAN VVIDMER.

